Hand held physiological signal acquisition device

ABSTRACT

A hand held, portable and multipurpose medical device for biological signals acquisition, display and storage. The device includes a multipurpose computerized apparatus ( 2 ) which is primarily used for computer games as well as a biological signals acquisition module ( 1 ) which uses a plurality of biological sensors ( 6 ). A cartridge ( 4 ) used in conjunction with the computerized apparatus is pre-programmed and includes a read only memory (ROM) for storage of the program and a random access memory (RAM) for storage of acquired data. The acquired data in one form is an ECG and the apparatus simultaneously acquires and displays the ECG waveform in “real time”. Multiple memories in the apparatus are used for storage of the acquired ECG and to enable output to a printer ( 8 ) for hard copy or to a PC for analysis and reporting.

The present invention relates to physiological monitoring of patientsand, in particular, to physiological signal acquisition apparatus whichprovides real time and/or simultaneous transmission and display of theacquired signals via a hand held electronic machine/display.

BACKGROUND TO THE INVENTION

Shifts in patient care, practices are changing the nature of monitoring.Increasingly, hospitals are attempting to lower costs by movinghigh-acuity patients as quickly as possible from intensive care units(ICU) to intermediate care and general ward areas.

This trend has dramatically reduced the need for the high endstationary, multi-parameter monitoring systems typically employed in theICU. This has intensified demand for a more flexible, and therefore lessexpensive, systems that can easily be integrated into lower-acuity areasand configured to individual patient needs.

This is particularly the case in heart monitoring where the ECG is thewell known form of monitoring.

Clinicians require rapid, sophisticated monitoring capability withoutcompromising diagnostic quality and at low cost. Therefore it would beadvantageous to provide a physiological signal monitor which is capableof providing real time acquisition and display of acquired signals via aportable, hand held electronic machine/display.

OBJECT OF THE INVENTION

It is an object of the present invention to provide a physiologicalsignal acquisition and display apparatus which substantially overcomesor ameliorates the above mentioned disadvantages. At the very least, theobject of the invention is to provide an alternative to knownphysiological signal acquisition and display apparatus.

DISCLOSURE OF THIE INVENTION

According to one aspect of the present invention there is disclosed aportable and multipurpose medical device for biological signalsacquisition, display and biological data storage, said devicecomprising:

a preprogrammed cartridge comprising:

a housing;

a connector partially disposed within the housing;

a read only memory (ROM) for storage of the program which has beenpreprogrammed;

a random access memory (RAM) for storage of acquired data;

a ROM—RAM parallel interface; and

a portable device comprising:

a second housing;

a slot connector being provided for insertion of the pre-programmedcartridge;

a display screen being provided on the second housing for displaying theacquired data;

a joy pad and control buttons disposed within the second housing tocontrol data acquisition options, horizontal and vertical scales of thedisplay, and other application specific functions of the medical device;and

a biological signals acquisition module comprising:

a third housing;

a plurality of biological sensors;

an analog circuit to amplify and pre-condition biological signals fromthe plurality of the biological sensors;

input/output interface to connect said third housing to said secondhousing;

a digital circuit for digitizing the biological signal and to send thebiological data through the connector regarding the biological datameans for storing the collected biological data in the RAM of the firsthousing.

According to another aspect of the present invention there is discloseda portable and multipurpose medical device for biological signalsacquisition, display and biological data storage, said devicecomprising:

a preprogrammed and a biological signals acquisition module comprising:

a housing;

a connector partially disposed within the housing;

a read only memory (ROM) for storage of the program which has beenpreprogrammed;

a random access memory (RAM) for storage of acquired data;

a ROM-RAM parallel interface;

a plurality of biological sensors;

an electrically isolated analog circuit to amplify and pre-conditionbiological signals from the plurality of the biological sensors;

a digital circuit for digitizing the biological signal and to send thebiological data through the connector regarding the biological datameans for storing the collected biological data in the RAM; and

a portable device comprising:

a second housing;

a slot connector being provided for insertion of the pre-programmedmodule;

a display screen being provided on the second housing for displaying theacquired data;

a joy pad and control buttons disposed within the second housing tocontrol data acquisition options, horizontal and vertical scales of thedisplay, and other application specific functions of the medical device.

Preferably, the display device is a hand-held computer display device,for example, a “NINTENDO GAMEBOY” (a registered trademark of NintendoCo. Ltd., of Kyoto, Japan, for one particularly well-known type ofhand-held computer display device) or similar apparatus.

Preferably, the physiological signal acquisition monitoring and displayapparatus is used to simultaneously acquire and physiological signalsfrom a plurality of sensors measuring at least one of the groupincluding multilead ECG, FECG, EEG, EMG, oximetry, blood pressurewhether detected by invasive or non-invasive means, respiration,temperature, phonocardiogram, tokolytic, blood glucose, pCO2, pO2 andpacemaker pulses, and condition the signals and transmit datarepresenting the signals in real time to an input/output port of thedisplay device.

Preferably, the circuit means includes an isolated section, anon-isolated section with an isolation barrier therebetween, theisolated section being isolated from the input/output port of thedisplay device. The isolated section receives the signals from thesensors and amplifies and preconditions the signals into data specificto the signal type prior to transmitting the data through the isolationbarrier.

Preferably, the non-isolated section receives the data transmittedthrough the isolation barrier and prepares the data for transmission toinput/output port of the display device via an input/output interface inthe first housing and a cable means to the input/output port of thedisplay device which is a second housing of the apparatus.

Preferably, the second housing is the Nintendo Game Boy® apparatus whichcomprises a microprocessor module, a display module, control means forusing internal data and program memory or providing connection to anexternal data and/or program memory, single or multiple input/outputports, display control and control devices.

Preferably, a Nintendo® Game Boy® video game system is used as thedisplay and control platform for various types of physiological dataacquisition devices.

When a new acquisition device is required it simply requires design ofthe acquisition hardware and associated application software to make anew product. To enable this the application software for each devicetype is written and stored in game module (CART) ROM.

The final product consists of the acquisition hardware (AcquisitionUnit), associated application software embedded in a game CART and theGame Boy® itself.

The Game Boy® combines a display/control system with an I/O interface tocreate a pocket size, low cost, diagnostic monitor.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be now be described with reference to theaccompanying drawings in which:

FIG. 1 is a diagram of the utilization of a portable ECG deviceaccording to a preferred embodiment;

FIG. 2 is a block diagram of an ECG acquisition module of the medicaldevice connected to the serial connector of Nintendo® Game Boy® videosystem device according to a preferred embodiment of the invention; and

FIG. 3 is a block diagram of an ECG acquisition module of the medicaldevice collected to the Nintendo® Game Boy® video system deviceaccording to another preferred embodiment of the invention.

BEST MODE OF CARRYING OUT THE INVENTION

In the preferred embodiment of the invention a Nintendo® Game Boy® videogame system is used as the display and control platform for theacquisition of the electrocardiogram (ECG). The Nintendo® Game Boy®device platform is manufactured and sold by Nintendo Co. Ltd., of Kyoto,Japan.

The electrocardiogram (ECG) is acquired from surface electrodes placedon the thorax in “standard monitoring” configuration or from directcontact to the thorax.

The Nintendo® Game Boy® device using an ECG application CART ie ROMcontaining pre-programmed software for ECG storage and display whencombined with an ECG acquisition module acquires the ECG whilesimultaneously displaying the ECG waveform in “real time”. Multiplememories in the Nintendo® Game Boy® device are used for storage of theacquired ECG. The memories also allow for the stored ECG to be outputtedto a printer for hard copy or to a PC for analysis and reporting.

The invention, however, is not limited to acquisition of ECG signalsonly. For example, FECG, EEG, EMG, oximetry, blood pressure whetherdetected by invasive or non-invasive means, respiration, temperature,phonocardiogram, tokolytic, blood glucose, pCO2, pO2 and pacemakerpulses.

In the preferred embodiments of the invention a handheld ECG monitoringsystem with the following characteristics is implemented:

Sample Rate: 200 Hz Resolution: 8 bit - 26 uV per bit Frequencyresponse: 0.05 Hz - 100 Hz Hardware Gain: 755 ECG Storage: Singlememory, 45 second duration, non-volatile, stored on game cart.

Referring to FIG. 1, a diagram of the operation of a portable ECG deviceaccording to a preferred embodiment is shown. The device includes an ECGacquisition module 1, a Nintendo® Game Boy® video game device 2 and aconnector 3 to the serial port of the Nintendo® Game Boy® video gamedevice 2. A pre-programmed cartridge 4 is inserted into the slot of theNintendo® Game Boy® video game device 2 while the ECG acquisition module1 is connected via a cable 5 and the connector 3 to the serial port ofthe Nintendo® Game Boy® video game device 2. The ECG acquisition module1 has a plurality of biological sensors 6.

ECG signals are collected via the sensors 6 from a patient 7 and afterprocessing by the ECG acquisition module 1 are sent to the serial portof the Nintendo® Game Boy® video game device 2 via cable 5 and connector3.

An application specific program is stored in the pre-programmedcartridge 4. The program controls ECG data retrieval from the ECGacquisition module 1, data storage, display, printout, user interfaceand sound functions of the Nintendo® Game Boy® video game device 2.

Acquired data can be displayed in real time, stored in the memory andprinted using a Nintendo® Game Boy® printer 8.

Using control buttons 9, the user can adjust horizontal and verticalscale of the display, freeze the picture, review recorded portions ofthe signal, enable or disable recording, initiate printout etc.

The configuration shown in FIG. 1 provides a diagnostic medical toolwith functionality defined by the pre-programmed cartridge 4 and by theacquisition module 1.

A block diagram of ECG acquisition module is shown in FIG. 2. The ECGsignal is collected via the sensors 6 and amplified by amplifier 10. Theamplifier 10 is DC biased by the virtual ground potential produced bythe virtual ground generator 11. The amplified analogue signal is fed tothe input of analogue to digital converter (ADC) 12. The ADC 12 has twocontrol inputs (-CS and CLK) and one output (DO). Control signals -CSand CLK are supplied by the Nintendo® Game Boy® device 2 via its serialport, the connector 3 and the cable 5 to a serial port interface 13 ofthe ECG acquisition module 1.

The amplified analogue signal is converted into digital ECG data (DO)and sent to the RAM of the pre-programmed cartridge 4 via the serialport interface 13 of the ECG acquisition module 1, the cable 5, theconnector 3 and internal circuitry of the Nintendo® Game Boy® device 2.

Digital ECG data being stored in the RAM are accessible for displaying,calculations and overwriting. Control and data signals flow is definedby the program stored in the ROM of the pre-programmed cartridge 4.

Referring to FIG. 3, a diagram of the operation of a portable ECG deviceaccording to another preferred embodiment is shown. The device includesan ECG acquisition module 21, a Nintendo® Game Boy® video game device 22and a connector 23 to the cartridge port of the Nintendo® Game Boy®video game device 22. The acquisition module 21 includes thepre-programmed cartridge which is inserted into the slot of theNintendo® Game Boy® video game device 22. The ECG acquisition module 21has a plurality of biological sensors 26.

ECG signals are collected via the sensors 26 from the patient and afterprocessing by the ECG acquisition module 21 are sent to the Nintendo®Game Boy® video game device 22 via its cartridge connector port.

An application specific program is stored in the pre-programmedcartridge. The program controls ECG data retrieval from the ECGacquisition module 21. data storage, display, printout, user interfaceand sound functions of the Nintendo® Game Boy® video game device 22.

Acquired data can be displayed in real time, stored in the memory andprinted using of Nintendo® Game Boy® printer 8.

Using control buttons 9, the user can adjust horizontal and verticalscale of the display, freeze the picture, review recorded portions ofthe signal, enable or disable recording, initiate printout etc.

The configuration shown in drawings provides a diagnostic medical toolwith functionality defined by the pre-programmed cartridge of theacquisition module 1.

A block diagram of ECG acquisition module is shown in FIG. 3. The ECGsignal is collected via the sensors 26 and amplified by amplifier 30.

Digital ECG data being stored in the RAM are accessible for displaying,calculations and overwriting. Control and data signals flow is definedby the program stored in the ROM of the pre-programmed cartridge 21.

Hardware Implementation

The ECG amplifier 10 is comprised of a high input impedance front stagevoltage followers, instrumentation amplifier high pass filter, secondamplification stage and a low pass anti-aliasing filter.

Front stage voltage followers use popular LMC6464 operational amplifierfrom National Semiconductors with input current less than 1 nA.

It is believed that the preferred embodiment as described meetsAAMI/ANSI ECG recommended safety standards which will include anelectrical isolation barrier 14 as seen in FIG. 2.

All digital signals are transferred via digital optical isolators. Ahigh pass filter defines the low end of the frequency band of theacquired ECG signal at 0.05 Hz. A low pass filter removes high frequencynoise on the input of ADC. Frequency response of the ECG amplifier 15selected for 0.05 Hz-100 Hz. 100 Hz high end frequency is defined by theselected sample rate of 200 Hz is in a compliance with the AAMI/ANSI ECGrecommended frequency response standards.

The ECG acquisition module 1 uses single positive voltage derived fromNintendo® Game Boy® device serial connector.

In order to amplify bipolar AC ECG signal without distortions, inputstage voltage followers and instrumentation amplifier are referenced toAMP_REF voltage=VCC/2 generated by the virtual ground generator 11.

Software Implementation

The software stored in the ROM of the pre-programmed cartridge 4 isexecuted by the microprocessor of the Nintendo® Game Boy® device 2. Inthe Nintendo® Game Boy® device 2, the processor is eight-bitmicroprocessor running at 4.19 MHz. Some of the peripheral functionssuch as serial communication (SPI), sound generation and local ROM areimplemented in the hardware of the microprocessor.

The software in a preferred embodiment is written in C and compiledusing the modified GNU compiler in the GameBoy SDK.

The following documents are used for Nintendo® Game Boy® applicationsoftware development:

Pan of ATX—Marat Fayzullin, Pascal Felber, Paul Robson Martin Korth—May3, 1998 Thorough description of GB hardware and software interface.

GameBoy Developer's Kit—V2.0.15. Pascal Felber Michael Hope May 10, 1998

GameBoy Assembly Language Commands

Virtual GameBoy The Portable Nintendo Emulator 1996 Marcel de Kogel,Marat Fayzul-lin, Thierry Lescot, Hans de Goede.

The software operates by setting the internal timer to interrupt at thesample rate (200 Hz). At each timer interrupt the software enables theADC via -CS line, it then sets the serial port to load one byte of datafrom the ADC. Once the data is loaded from the ADC the ADC is disabledvia -CS. The data is then stored, displayed and processed as desired.

The components used are all commonly available, however, the inventionis not particularly limited to any specific component.

The portable modular diagnostic medical system has been described. Thesystem is portable in that it is based on a portable handheld Nintendo®Game Boy® device. The system is modular in that different pre-programmedcartridges having different diagnostic medical applications can beplugged into the Nintendo® Game Boy® device along with appropriatebio-acquisition module.

The device is simple to operate. In the preferred embodiments described,ECG waveforms can be stored in the RAM or displayed on the screenon-line in real time. This provides options for long term storage of thebiological data, review, printout or transmission of the stored data tothe computer.

The foregoing describes only one embodiment of the present invention,and modifications obvious to those skilled in the art can be madethereto without departing from the scope of the present invention.

What is claimed is:
 1. A portable and multipurpose medical device forbiological signals acquisition, display and biological data storage,said medical device comprising: a preprogrammed and a biological signalsacquisition module comprising: a housing; a connector partially disposedwithin the housing; a read only memory (ROM) for storage of the programwhich has been preprogrammed; a random access memory (RAM) for storageof acquired data; a ROM-RAM parallel interface; a plurality ofbiological sensors for measuring at least two biological parameters ofthe group comprising multilead ECG, FECG, EEG, EMG, oximetry, bloodpressure, respiration, temperature, phonocardiogram, tokolytic, bloodglucose, pCO₂, pO₂ and pacemaker pulses, at least one biological sensorof said plurality of biological sensors being an ECG sensor formonitoring said ECG; an electrically isolated analog circuit foramplifying and pre-conditioning biological signals from the plurality ofthe biological sensors; an ECG amplifier for amplifying an ECG signalfrom said sensor for monitoring said ECG; a digital circuit fordigitizing the biological signal and for sending the biological datathrough the connector of said preprogrammed and a biological signalsacquisition module for storing the collected biological data in the RAM;and, a portable device comprising: a second housing; a slot connectorbeing provided for insertion of the preprogrammed module; a displayscreen being provided on the second housing for displaying the acquireddata; and, a joy pad and control buttons disposed within the secondhousing to control data acquisition options, horizontal and verticalscales of the display screen.
 2. The portable and multi-purpose medicaldevice for biological signals acquisition, display and biological datastorage according to claim 1, wherein the portable device is a hand-heldgame device.
 3. The portable and multi-purpose medical device forbiological signals acquisition, display and biological data storageaccording to claim 1, wherein said electrically isolated analog circuitincludes an isolated section, a non-isolated section with an isolationbarrier therebetween, the isolated section being isolated from theinput-output port of the display screen.
 4. The portable andmulti-purpose medical device for biological signals acquisition, displayand biological data storage according to claim 3, wherein the isolatedsection receives the signals from said plurality of biological sensorsand amplifies and preconditions the signals into data specific to thesignal type prior to transmitting the data through the isolationbarrier.
 5. The portable and multi-purpose medical device for biologicalsignals acquisition display and biological data storage according toclaim 3, wherein the non-isolated section receives the data transmittedthrough the isolation barrier and prepares the data for transmission toan input/output port of the display screen via an input/output interfacein said first housing and cable means to the input/output of the displayscreen in said second housing.
 6. The portable and multi-purpose medicaldevice for biological signals acquisition, display and biological datastorage according to claim 1, wherein said ECG amplifier comprises ahigh-input impedance front stage voltage follower, an instrumentationamplifier, a high pass filter, an additional amplification stage and alow pass anti-aliasing filter.
 7. A portable and multipurpose medicaldevice for biological signals acquisition, display and biological datastorage, said medical device comprising: a preprogrammed cartridgecomprising: a first housing; a connector partially disposed within saidhousing; a read only memory (ROM) for storing software preprogrammed onsaid preprogrammed cartridge; a random access memory (RAM) for storageof acquired data; and, a ROM-RAM parallel interface; a portable devicecomprising: a second housing; a slot connector for insertion of saidpreprogrammed cartridge; a display screen on said second housing fordisplaying the acquired data; and, a joy pad and control buttons withinsaid second housing for controlling data acquisition options, horizontaland vertical scales of said display screen; and, a biological signalsacquisition module comprising: a third housing; a plurality ofbiological sensors for measuring at least two biological parameters ofthe group comprising multilead ECG, FECG, EEG, EMG, oximetry, bloodpressure, respiration, temperature, phono-cardiogram, tokolytic, bloodglucose, pCO₂, pO₂ and pacemaker pulses, at least one biological sensorof said plurality of biological sensors being an ECG sensor formonitoring said ECG; an analog circuit for amplifying andpre-conditioning biological signals from said plurality of thebiological sensors; an ECG amplifier for amplifying an ECG signal fromsaid sensor for monitoring said ECG; an input/output interface forconnecting said third housing to said second housing; and, a digitalcircuit for digitizing the biological signal and for sending thebiological data through said connector of said preprogrammed cartridgefor storing the collected biological data in the RAM of said firsthousing.
 8. The portable and multi-purpose medical device for biologicalsignals acquisition, display and biological data storage according toclaim 7, wherein the portable device is a hand-held game device.
 9. Theportable and multi-purpose medical device for biological signalsacquisition, display and biological data storage according to claim 7,wherein said analog circuit includes an isolated section, a non-isolatedsection with an isolation barrier therebetween, the isolated sectionbeing isolated from the input-output port of the display screen.
 10. Theportable and multi-purpose medical device for biological signalsacquisition, display and biological data storage according to claim 9,wherein the isolated section receives the signals from said plurality ofbiological sensors and amplifies and preconditions the signals into dataspecific to the signal type prior to transmitting the data through theisolation barrier.
 11. The portable and multi-purpose medical device forbiological signals acquisition, display and biological data storageaccording to claim 9, wherein the non-isolated section receives the datatransmitted through the isolation barrier and prepares the data fortransmission to an input/output port of the display screen via aninput/output interface in said first housing and cable means to theinput/output of the display screen in said second housing.
 12. Theportable and multi-purpose medical device for biological signalsacquisition, display and biological data storage according to claim 7,wherein said ECG amplifier comprises a high-input impedance front stagevoltage follower, an instrumentation amplifier, a high pass filter, anadditional amplification stage and a low pass anti-aliasing filter.